![Johan Hovold](/assets/img/avatar_default.png)
Simplify the endpoint sanity check by letting core verify that the required endpoints are present. Signed-off-by: Johan Hovold <johan@kernel.org>
198 lines
4.7 KiB
C
198 lines
4.7 KiB
C
/*
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* Symbol USB barcode to serial driver
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*
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* Copyright (C) 2013 Johan Hovold <jhovold@gmail.com>
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* Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
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* Copyright (C) 2009 Novell Inc.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/tty.h>
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#include <linux/slab.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_flip.h>
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#include <linux/module.h>
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#include <linux/usb.h>
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#include <linux/usb/serial.h>
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#include <linux/uaccess.h>
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static const struct usb_device_id id_table[] = {
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{ USB_DEVICE(0x05e0, 0x0600) },
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{ },
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};
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MODULE_DEVICE_TABLE(usb, id_table);
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struct symbol_private {
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spinlock_t lock; /* protects the following flags */
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bool throttled;
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bool actually_throttled;
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};
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static void symbol_int_callback(struct urb *urb)
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{
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struct usb_serial_port *port = urb->context;
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struct symbol_private *priv = usb_get_serial_port_data(port);
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unsigned char *data = urb->transfer_buffer;
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int status = urb->status;
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int result;
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int data_length;
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switch (status) {
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case 0:
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/* success */
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break;
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case -ECONNRESET:
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case -ENOENT:
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case -ESHUTDOWN:
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/* this urb is terminated, clean up */
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dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
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__func__, status);
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return;
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default:
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dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
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__func__, status);
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goto exit;
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}
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usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
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/*
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* Data from the device comes with a 1 byte header:
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*
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* <size of data> <data>...
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*/
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if (urb->actual_length > 1) {
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data_length = data[0];
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if (data_length > (urb->actual_length - 1))
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data_length = urb->actual_length - 1;
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tty_insert_flip_string(&port->port, &data[1], data_length);
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tty_flip_buffer_push(&port->port);
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} else {
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dev_dbg(&port->dev, "%s - short packet\n", __func__);
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}
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exit:
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spin_lock(&priv->lock);
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/* Continue trying to always read if we should */
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if (!priv->throttled) {
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result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
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if (result)
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dev_err(&port->dev,
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"%s - failed resubmitting read urb, error %d\n",
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__func__, result);
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} else
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priv->actually_throttled = true;
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spin_unlock(&priv->lock);
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}
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static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
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{
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struct symbol_private *priv = usb_get_serial_port_data(port);
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unsigned long flags;
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int result = 0;
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spin_lock_irqsave(&priv->lock, flags);
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priv->throttled = false;
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priv->actually_throttled = false;
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spin_unlock_irqrestore(&priv->lock, flags);
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/* Start reading from the device */
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result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
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if (result)
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dev_err(&port->dev,
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"%s - failed resubmitting read urb, error %d\n",
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__func__, result);
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return result;
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}
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static void symbol_close(struct usb_serial_port *port)
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{
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usb_kill_urb(port->interrupt_in_urb);
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}
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static void symbol_throttle(struct tty_struct *tty)
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{
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struct usb_serial_port *port = tty->driver_data;
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struct symbol_private *priv = usb_get_serial_port_data(port);
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spin_lock_irq(&priv->lock);
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priv->throttled = true;
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spin_unlock_irq(&priv->lock);
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}
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static void symbol_unthrottle(struct tty_struct *tty)
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{
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struct usb_serial_port *port = tty->driver_data;
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struct symbol_private *priv = usb_get_serial_port_data(port);
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int result;
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bool was_throttled;
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spin_lock_irq(&priv->lock);
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priv->throttled = false;
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was_throttled = priv->actually_throttled;
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priv->actually_throttled = false;
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spin_unlock_irq(&priv->lock);
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if (was_throttled) {
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result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
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if (result)
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dev_err(&port->dev,
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"%s - failed submitting read urb, error %d\n",
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__func__, result);
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}
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}
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static int symbol_port_probe(struct usb_serial_port *port)
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{
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struct symbol_private *priv;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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spin_lock_init(&priv->lock);
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usb_set_serial_port_data(port, priv);
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return 0;
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}
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static int symbol_port_remove(struct usb_serial_port *port)
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{
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struct symbol_private *priv = usb_get_serial_port_data(port);
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kfree(priv);
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return 0;
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}
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static struct usb_serial_driver symbol_device = {
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.driver = {
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.owner = THIS_MODULE,
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.name = "symbol",
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},
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.id_table = id_table,
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.num_ports = 1,
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.num_interrupt_in = 1,
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.port_probe = symbol_port_probe,
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.port_remove = symbol_port_remove,
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.open = symbol_open,
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.close = symbol_close,
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.throttle = symbol_throttle,
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.unthrottle = symbol_unthrottle,
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.read_int_callback = symbol_int_callback,
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};
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static struct usb_serial_driver * const serial_drivers[] = {
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&symbol_device, NULL
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};
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module_usb_serial_driver(serial_drivers, id_table);
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MODULE_LICENSE("GPL");
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